Monday, July 30, 2007

The prosthetic limb revolution has arrived

Last week, a Scottish company called Touch Bionics unveiled a "bionic hand" for amputees, called the i-LIMB.

It is billed as the most sophisticated prosthetic hand commercial available, as it lets the wearer assume different grips by sensing electrical impulses in the muscles in their upper arm. Even delicate grips, such as holding a key are possible, (see image, left).

You can see it in action, and hear a bit more about its capabilities, in the video below, which we created from footage provided by Touch Bionics.

It's an impressive-looking device, and it certainly seems to have made a big impression on those who have tested it. But it's also just one of many novel prosthetic technologies out there. Here's a quick round-up of some other interesting projects from around the world.

Small sensors fitted to each fingertip let the hand know when an object is being gripped too tightly or too gently, and even if it's too hot to handle. Currently, the hand must be programmed to respond to this information. But eventually, the researchers believe this sensory information could be fed directly back to the wearer.

In the US, a woman called Claudia Mitchel is testing a whole-arm prosthetic, which was developed by researchers at the Rehabilitation Institute of Chicago. The arm connects to muscles in her chest, rather than her upper arm, requiring various muscle nerves to be "rewired" beforehand. Eventually, however, this set-up could also let her "feel" feedback from the arm.

And finally, a thought-controlled bionic limb is being developed by a Massachusetts-based company called Cyberkinetics. The company has implanted 100-electrodes on top of the motor cortex of a paralysed man called Matt Nagle, allowing him to operate a computer, or a prosthetic arm, using his thoughts. An recent article from New Scientist magazine describes this project and similar efforts to connect prosthetics to the brain - Artificial limbs wired direct to the brain (subscription required).